Disable Log4J's built-in shutdown hook, because it broke logging in the shutdown sequence when exiting by interrupting the process. This was caused by the Log4J's hook running before ours. (#637)

proxy/src/main/java/com/velocitypowered/proxy/VelocityServer.java

@@ -502,6 +502,9 @@ public class VelocityServer implements ProxyServer, ForwardingAudience {
         Thread.currentThread().interrupt();
       }
 
+      // Since we manually removed the shutdown hook, we need to handle the shutdown ourselves.
+      LogManager.shutdown();
+
       shutdown = true;
 
       if (explicitExit) {

proxy/src/main/resources/log4j2.xml

@@ -16,7 +16,8 @@
     along with this program.  If not, see <https://www.gnu.org/licenses/>.
 -->
 
-<Configuration status="warn">
+<!-- Disable shutdown hook, because we have our own -->
+<Configuration status="warn" shutdownHook="disable">
   <Appenders>
     <TerminalConsole name="TerminalConsole">
       <PatternLayout>